Heat dissipator apparatus



Filed Oct. 22, 1965 Sept. 19, 1967 isk ETAL 3,342,255

' -HBAT 'DIss I AT oR APPARATUS I 2 Sheets-Sheet l i 2* "52 ll 1a h I'llli O HM, r O

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174 LEM 15a J L I 41 42 -25 'lBa 15a FIG. 2

' ,INVENTORS GEORGE RISK F aAYMOND c. ROOT ATTORNEY Sept 19, 1967 K Eng3,342,255

HEAT DIS S IPATOR APPARATUS Ffile'd Oct. 22, 1965 2 Sheets-Sheet 2 INVEN T0 R5 ROOT ATTOR NEY United States Patent O 3,342,255 HEATDISSIPATOR APPARATUS George Risk and Raymond C. Root, Columbus, Nebr.,assignors to Richleu iorporation, Columbus, Nebr., a cor oration ofNebras a p Filed Oct. 22, 1965, Ser. No. 501,498

Claims. (Cl. 165-80) This invention relates to heat dissipatorapparatuses for transistors and other heat generating electroniccomponents. In particular, this invention relates to a highly efficientheat dissipator apparatus of multi-segment tubular construction, therespective segments being especially adaptable for quick and simpleassembly, disassembly, and re-assembly as required for manufacture andunder actual use conditions.

Heat dissipator apparatuses of generally tubular shape are very commonlyemployed in electronic circuits. These tubular shaped apparatusesinvariably include a plurality of heat dissipator ribs or fins that arein a heat conductive relationship with the main tubular body, said ribsor fins being disposed either at the interior or at the exterior of thetubular structure. Tubular shaped heat dissipator apparatuses may bereadily employed either as a so-called natural convection unit (in whichcase the apparatus is vertically arranged in chimney-like fashion) or asa socalled forced air unit (in which case a powered fan is used to coolthe heat dissipator ribs). In either case, the tubular heat dissipatorapparatus is, of course, firmly bolted or otherwise attached Within theelectronic circuit package.

Within the past several years, the segmentized tubular heat dissipatorapparatus has become quite popular in the electronics industry. Eachsegment of the segmentized tubular structure commonly comprises a webthat provides an arcuate or chordal peripheral portion of the tube. Oneof the web sides, usually the interior side, is provided with aplurality of heat dissipator ribs; another of the web sides, usually theexterior side, is provided with a support member or station adapted tocarry a transistor or other heat-generating electronic component.Ordinarily the peripheral web, the heat dissipator ribs, and the supportmember are provided of a structurally-continuous uniphase material e.g.extruded aluminum, so that the necessarily continuous heat-conductivepath exists among the three components of each segment. Because theseveral segments of the tubular heat dissipator apparatus are commonlyof electrically-conductive metal, and because it is necessary toelectrically isolate every electronic component mounted on therespective support members, it is accordingly appropriate that therespective segments be attached together in an electrically-insulatedrelationship. The multi-segment tubular heat sinks of the prior art areexceedingly complex to assemble because of the cumbersome paraphernalianecessary to electrically isolate the respective segments.

There are, of course, a multitude of kinds and sizes of heat generatingelectronic components, and accordingly, any one of a multitude membersmight be required within any given tubular heat sink. Thus, if a heatgenerating component of an original electronic circuit is to be laterreplaced with a different type of heat generating component, then it iscommonly necessary to disassemble the tubular heat sink so as to replaceone of the original segments with another having a more appropriatesupport member. With the prior art devices it is necessary to remove theentire tubular heat sink from the circuit package to replace one ofsegments with a difierent type segment, and this operation is notpermissible, or is at least very impractical, in many situations.

It is accordingly an object of the present invention to provide amulti-segment tubular heat sink that is exceedingly simple to assemblein such form that the respect1ve segments are electrically-insulated,one from the other.

It is another object of the present invention to provide amulti-se-grnent tubular heat sink wherein one or more of the segmentsmay be substituted by alternate configuration segments without thenecessity for removing the entire heat dissipator apparatus from theelectrical circult package.

It is another object of the present invention to provide a new andefiicient design for the heat dissipator ribs of the tubular heat sink.

It is yet another object of the present invention to provide asegmentized cooling device which may be tailored to a wide range ofapplications.

These and other objects and advantages are attained by means of novelconfigurations for the respective segments of the tubular heat sink,including novel rib members, together with a unique yet simple andconvenient means for assembling the respective segments together.

In the drawing, wherein like numbers refer to like parts in the severalviews, and in which:

FIGURE 1 is a top plan view of a representative form of the tubular typeheat dissipator apparatus of the present invention.

FIGURE 2 is a side elevational view of the heat dissipator apparatus ofthe :present invention.

FIGURE 3 is a front elevational view of the heat dissipator apparatusshown in FIGURES 1 and 2.

FIGURE 4 is a front elevational view as in FIGURE 3 but with the forwardand rearward end plates and gaskets removed to show details ofconstruction for the several segments.

FIGURE 5 is a perspective view of a shelf type segment member of thetubular heat sink.

FIGURE 6 is a perspective view of a stud type segment member of thetubular heat sink.

FIGURE 7 is an exploded perspective view of the preferred type ofinter-segments spacer employed.

FIGURE 8 is an exploded perspective view of another form of theinter-segments spacer employed.

The tubular heat dissipator apparatus 10 comprises four distinct websegments 20, 30, 40, and 50, that are interconnected together in atubular relationship with intersegment electrically-insulative spacermeans '60, 70, 80, and to provide a laterally closed structure havingtwo open ends, including a forward end 11 and a rearward end 12.Integrally connected to the multi-seg-ment tubular structure are a pairof electrically-isolated end plates, including a forward plate 15 and arearward plate 16. Each of the web segments at least partially surroundslongitudinal central axis 13 in arcuate or chordal fashion, said axis 13being substantially parallel to the respective webs.

One of the sides (preferably the interior side) of the rnulti-segmentlaterally enclosed conduit or tube is provided with a plurality of heatdissipator ribs spaced at subratus.

"the several web segments is provided with an integral support memberadapted to carry a heat generating electronic component. Because it isnecessary that there be an uninterrupted heat-conductive path betweenthe support member, the base web, and the heat dissipator ribs, it isdesirable that these three components be integrally provided of astructurally-continuous piece of metal or other heat-conductive metal.Appropriate to this uniphase type of integral construction are metallicextrusions of the types described in the following paragraph.

Arcuate web segment 20 is integrally provided with an externalrectangular shelf support member 21 and a plurality of integral ribsthat extend radially toward the longitudinal central axis 13 of thesegmentized conduit structure 10. Support member 21 is provided with aperforation 22 therethrough to facilitate mounting of a transistor orother heat generating electronic component thereon. Arcuate Web segment30 is integrally provided with an external stud-type rectangular supportmember 31 and a plurality of integral ribs that extend towardlongitudinal central axis 13. Threaded perforation 32 of support member31 is radial with respect to axis 13 and extends into stud-type supportmember 31. Angular or chordal web segment 40 is integrally provided withan external rectangular shelf-type support member 41 having perforation42 and a plurality of ribs that extend toward central axis 13. Arcuateweb segment 50 is integrally provided with an external stud-typerectangular support member 51 and a plurality of ribs that extend towardcentral axis 13. Perforation 52 of support member 51 is radial withrespect to axis 13 and extends into stud-type support member 51.Segments 20, 30, 40 and 50 are each of the same thickness, along centralaxis 13, between end gaskets 25 and 26.

The respective metallic conduit segments are removably connectedtogether in the required electrically-insulative relationship with novelslidable spacer means located at the juncture between every respectivesegment. One type of electrically-insulative slidable connector employedis that illustrated in FIGURE 8 and which is employed at the 20-50 andat the 30-40 segment junctures. Spacer 60 at the 30-40 juncturecomprises a metallic rigid intermediate plate 61 and a pair of metallicterminal sockets 62 and 63, said terminal sockets being of a flaredcrosssectional shape and being integrally connected to plate 61. A stripof pressure-sensitive electrically insulative .tape 64 e.g. adhesivelycoated Teflon is adherently attached over trapezoidal sockets 62 and 63so as to provide electrically-insulative terminii for spacer 60.Electrically insulated socket 62 is slidably engaged within a matingtrapezoidal slot 34 at that end of segment 30 adjacent to segment 40,while electrically-insulative socket 63 is similarly slidably engagedwithin a mating trapezoidal .slot 43 at that end of segment 40 adjacentto segment 30. Slots 34 and 43, as well as hereinafter described slots23, 24, 33, 44, 53, and 54, are each parallel to longitudinal centralaxis 13 and are each coextensive with the frontto-rear thickness oftheir respective segments. As can best be seen in the FIGURE 2 sideelevational view, connector 60 is coextensive with the front-to-rearthickness of adjacent segments 30 and 40 between end gaskets 25 and 26.Connector 70, which is employed at the 20-50 segment junctures, isidentical to connector 60 except that the rigid intermediate plate 71and the terminal sockets 72 and 73 are moldably formed of a hardelectrically-insulative resin e.g. phenol-formaldehyde copolymer, andthere is accordingly no need for terminal insulator tapes. Socket 72 isslidably engaged within a mating trapezoidal slot 23 at that end ofsegment 20 adjacent to segment 50, while socket 73 is similarly slidablyengaged within -a mating trapezoidal slot 54 at that end of segment 50adjacent to segment 20.

The preferred type slidable. connector is that illustrated in FIGURE 7and which is employed at the 20-30 and at the 40-50 segment junctures.Specifically, connector 80 4 comprises a rigid metallic intermediateplate 81 and a pair of metallic terminal sockets 82 and 83, saidterminal sockets being integrally connected to plate 81. Sockets 82 and83 are each provided with a longitudinal groove 85 that is coextensivebetween the front and rearward surfaces of connector 80. Plate 81 andsockets 82 and 83, together with grooves 85, are preferably extrudedfrom a structurally-continuous metal e.g. aluminum. A strip ofpressure-sensitive electrically insulative tape 84 e.g. adhesivelycoated Teflon is adherently attached over sockets 82 and 83 so as toprovide electrically-insulative terminii for spacer-connector 80.Electrically-insulative socket 82 is slidably engaged within a matingslot 24 at the outward or exterior surface of segment 20 near shelf-likesupport member 21. Electrically-insulated socket 83 is similarlyslidably engaged within .a mating slot 33 at the exterior surface ofsegment 30 near stud-type support member 31. As can best be seen in theFIGURE 1 top plan view, connector 80 is coextensive with thefront-to-rear thickness of adjacent segments 20 and 30, and the rigidintermediate plate 81 overlies the spatial gap between segments 20 and30. Connector 90, which is employed at the 40-50 segment junctures, isidentical to connector 80 except that the rigid intermediate plate 91and the terminal sockets 92 and 93 including longitudinal grooves 95 aremoldably formed of a hard electrically-insulative resin, and there isaccordingly no need for terminal insulator tapes 84. Socket 92 isslidably engaged within a mating slot 53 at the outward surface ofsegment 50 near stud type support member 51, while socket 93 issimilarly slidably engaged within a mating slot 44 at the outwardsurface of segment 40 near shelf-like support member 41. As withconnector 80, connector is coextensive with the front-to-rear thicknessof adjacent segments 40 and 50, and the rigid intermediate plate 91overlies the spatial gap between segments 40 and 50. Thus, slidableconnectors 60, 70, 80, and 90 do maintain the segments 20, 30, 40 and 50in fixed peripheral positions with respect to longitudinal central axis13. V

The longitudinal relationship of the several segments are fixablymaintained with forward and rearward face plates 15 and 16,respectively, together with a plurality of self-tapping screws 17threadedly engaged with grooved portions 85 and of connectors 80 and 90.Face plates 15 and 16 are each of a rectangular plate-like nature havinga central circular opening that surrounds central axis 13 and that issubstantially coextensive with the interior of the multi-segmentconduit. As can best be seen in the FIGURES 1 and 2 plan and elevationalviews, face plates 15 and 16 are of greater breadth than themulti-segment conduit shown in FIGURE 4. Face plates 15 and 16 areprovided with lower perforate flanges 15a and 16a, respectively, tofacilitate mounting of the tubular heat dissipator apparatus with screwsor other removable fasteners into the electrical circuit package. Endplates 15 and 16 are normally of metallic structural material forconvenience in manufacture, and accordingly to prevent the metallicplates from destroying the intersegments electrical isolation, suitableelectrically-insulative gaskets are disposed between the end plates andthe multi-segment tubular structure. Specifically a thin annular rubbergasket 25 is disposed against forward end plate 15, and a similarannular gasket 26 is abuttably disposed between rearward end plate 16and the several segments of the multisegment tubular structure. 7

End plates 15 and 16 are provided with a plurality of perforations thatare in registry with grooves 85 and 95 within each of the respectiveslidable spacer-connectors 80 and 90. Self-tapping screws 17, passingthrough a perforation, through an annular gasket insulator 25 or 26, andthence into a socket groove 85 or 95 of the slidable connector, hold endplates 15 and 16 within the structure so as to prevent longitudinalslidability of the several segments of the multi-se'gment tube. Asscrews 17 thread into the sockets, the socket expands against itssurrounding groove e.g. 82 within 24. The length of self-tapping screws17 is less than one-half the longitudinal length of the heat dissipatorapparatus (between gaskets 25 and 26) because two of such opposed screws17 are threadably engaged within a single socket of the slidableconnector, one screw entering from either end of each socket. Whilegrooves 85 and 95 have been employed within the sockets, centrallongitudinal holes would also provide a longitudinal perforation toserve the same purpose; the grooved socket is preferred because thisconnector embodiment may be formed as an economical extrusion.

Spacer-connectors 60 and 70 could also be provided with grooves or holesfor accommodation of fastener means e.g. screws 17, as indicated inphantom line in FIGURE 8. However, not every slidable-connector needs tobe attached to an end plate, and so long as at least two diametricallyopposed screws are employed, this is sufficient for attachment of theend plates.

As previously mentioned, the apparatus is typically attached within acircuit package with screws (not shown) passing through the perforateend plate flanges a and 16a. Now in order to be able to replace one ofthe segments -50 inclusive without removing the entire structure 10 fromthe circuit package, preferably only one of the flanges e.g. 15a, isattached. Then, when it is desired to remove one of the segments andreplace it with an other, the opposite end plate e.g. 16, is entirelyremoved along with its screw fasteners 17. The fastened end plate 15remains within the circuit package. Then, only those screws 17 holdingthe appropriate segment to end plate 15 are removed to free theappropriate slidable-connector. After the appropriate segment is removedand replaced with another, its slidable-connector, end plate 16 andscrews 17 are re-assembled, followed by re-mounting of end plate flange16a. Thus a heat sink segment may be readily replaced with another insitu without the necessity for dismounting the whole unit from thecircuit package.

From the foregoing, the construction and operation of the heatdissipator apparatus will be readily understood and further explanationis believed to be unnecessary. However, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the appended claims.

We claim:

1. A heat dissipator apparatus comprising a tubular member that islaterally enclosed and longitudinally open, the lateral confines of saidconduit comprising a plurality of adjacently disposed heat-conductiveweb segments connected together about the tube longitudinal central axiswith electrically-insulative rigid spacer means located at the juncturebetween every adjacent web segment, a plurality of said heat-conductiveweb segments each being provided with a plurality of heat dissipatorribs spaced along one of the sides of said web segment, said heatdissipator ribs being in heat-conductive relationship with said websegment, each web segment being provided with a pair of longitudinalgrooves each being substantially parallel to the conduit longitudinalcentral axis, said grooves having linearly generated sidewalls, saidspacer means cooperating with said grooves to removably support andspace said web segments about the tube longitudinal central axis theopposite side of at least one web segment being integrally provided withat least one support member adapted to carry a heat generatingelectronic component, said at least one support member being inheat-conductive relationship to said web segment, saidelectrically-insulative spacer means comprising an intermediate portionand a pair of terminal socket members, each of said terminal socketmembers being securely surrounded with an elongate groove of adjacentlydisposed web segments, the intermediate portion of the spacer meansbeing disposed at the juncture of the respective adjacent web segments.

2. The heat dissipator apparatus of claim 1 wherein the intermediateportion and the two terminal socket members of the spacer means comprisean electricallyinsulative resinous material.

3. A heat dissipator apparatus comprising a generally cylindricalconduit that is laterally enclosed and longitudinally open, the lateralboundary of said conduit compring a plurality of adjacently disposedheat-conductive arcuate web segments connected together about the conduit longitudinal central axis with spacer means located at the juncturebetween every web segment, each of said heat-conductive arcuate websegments being provided with a plurality of heat dissipator ribs spacedalong the interior side of said arcuate web segments, within theinternal confines of the conduit, said heat dissipator ribs being inheat-conductive relationship with said arcuate web segments andextending therefrom towards the longitudinal central axis of saidgenerally cylindrical circuit, the exterior side of each web segmentbeing provided with a pair of longitudinal grooves each beingsubstantially parallel to the conduit longitudinal central axis, saidgrooves having linearly generated sidewalls, the exterior side of eacharcuate web segment being integrally provided with a least one supportmember adapted to carry a heat generating electronic component, said atleast one support member being disposed between said exterior groovesand being in heat-conductive relationship with said arcuate web segment,said spacer means comprising a rigid intermediate portion and a pair ofterminal elongate socket members, said socket members being resilientlydeformable normal to the elongate axis thereof, said socket membershaving an electrically-insulative exterior surface, each of saidterminal socket members being securely surrounded by the exteriorgrooved portion of the arcuate web segments, the rigid intermediateportion of the spacer means being disposed at the juncture of theadjacently disposed arcuate web segments whereby said spacer meansremovably support and space said web segments about the conduitlongitudinal central axis.

4. A heat dissipator apparatus comprising a tubular conduit member thatis laterally enclosed and longitudinally open, the lateral boundary ofsaid conduit member comprising a plurality of adjacently disposed websegments connected together about the conduit longitudinal central axiswith electrically-insulative rigid spacer means located at the juncturebetween every adjacent web segment, a plurality of said heat-conductiveweb segments being each provided with a plurality of heat dissipatorribs spaced at substantially regular intervals along a side of said websegments within the internal confines of said tubular conduit member,said heat dissipator ribs being in heat-conductive uni-phaserelationship with its web segment, said ribs being radially disposedwith respect to the conduit longitudinal central axis, the length of anyone heat dissipator rib being less than the distance between itsintegrally connected web and the conduit longitudinal axis, alternateshorter members of said ribs being less than about one half the lengthof the intervening longer rib members, each web segment being providedwith a pair of longitudinal grooves each groove being substantiallyparallel to the conduit longitudinal central axis, said grooves havinglinearly generated sidewalls, that side of at least one web segmentexterior of the conduit being integrally provided with at least onesupport member adapted to carry a heat generating electronic component,said at least one support member being in heat-conductive uni-phaserelationship with said web segment, said electrically-insulative spacermeans each comprising an intermediate portion and a pair of terminalsocket members, each of said terminal socket members being securelysurrounded with an elongate groove of adjacently disposed web segments,the intermediate portion of the spacer means being disposed at thejuncture of the respective adjacent web segments whereby said spacermeans removably support and space said web segments about the tubularconduit longitudinal central axis.

5. A heat dissipator apparatus comprising a tubular conduit member thatis laterally enclosed and longitudinally open between its forward andrearward ends, the lateral boundary of said conduit member comprising aplurality of adjacently disposed web segments connected together aboutthe conduit longitudinal axis, there being electrically-insulativespacer means located at the junctures of the respective adjacent websegments on the external side of the conduit member, whereby said spacermeans removably support and space said web segments about the conduitlongitudinal central axis a plurality of said heat-conductive websegments being each provided with a plurality of heat dissipator ribsspaced at substantially regular intervals along the internal side ofsaid web segments within the internal confines of the tubular conduitmember provided by the interconnected web segments, the length of anyone respective rib being less than the distance between its web and theconduit longitudinal axis, the respective heat dissipator ribs being ofalternately long and short lengths to provide a staggered configurationfor the ribs, the alternating shorter ribs being less than aboutone-half the length of the longer ribs, a plurality of saidheat-conductive web segments being each provided with at least onesupport member at the external side of the web segment, said externallydisposed support members being in heat-conductive uni-phase relationshipwith respect to the web segment and being adapted to carry aheat-generating electronic component, a plurality of saidheat-conductive web segments being each provided with a pair oflongitudinally disposed elongate grooves on the web segment externalside, each elongate groove extending between the forward and rearwardends of the tubular conduit member provided by the interconnected websegments, electrically-insulative elongate sockets slidably engagedwithin said elongate grooves, said elongate sockets being longitudinallyperforate, and a pair of opposed face plates positioned at the rearwardand forward ends of the tubular conduit member provided by theinterconnected web segments so as to maintain the longitudinalrelationship of the several web segments, each of said face plateshaving a central opening that surrounds the conduit longitudinal axis,each of said face plates having a plurality of perforations that are inregistry with the longitudinal perforations of the slidably engagedelongate socket members, and said face plates being held in opposedrelationship by means of opposed screws threadedly engaged with thelongitudinally perforate portion of the same socket, said opposed screwsentering the same socket from the respective ends thereof, the length ofeach opposed screw being less than onehalf the longitudinal length ofthe heat dissipator apparatus.

References Cited UNITED STATES PATENTS 2,109,279 2/1938 Soverhill 2193652,815,472 12/1957 Jackson et a1 3l7-100 X 2,930,405 3/1960 Welsh -179 X3,149,666 9/1964 Coe 165-121 3,220,471 11/1965 Coe 165-121 3,227,34610/1966 McAdams et al. 165185 X ROBERT A. OLEARY, Primary Examiner. A.W. DAVIS ]R., Assistant Examiner.

1. A HEAT DISSIPATOR APPARATUS COMPRISING A TUBULAR MEMBER THAT ISLATERALLY ENCLOSED AND LONGITUDINALLY OPEN, THE LATERAL CONFINES OF SAIDCONDUIT COMPRISING A PLURALITY OF ADJACENTLY DISPOSED HEAT-CONDUCTIVEWEB SEGMENTS CONNECTED TOGETHER ABOUT THE TUBE LONGITUDINAL CENTRAL AXISWITH ELECTRICALLY-INSULATIVE RIGID SPACER MEANS LOCATED AT THE JUNCTUREBETWEEN EVERY ADJACENT WEB SEGMENT, A PLURALITY OF SAID HEAT-CONDUCTIVEWEB SEGMENTS EACH BEING PROVIDED WITH A PLURALITY OF HEAT DISSIPATORRIBS SPACED ALONG ONE OF THE SIDES OF SAID WEB SEGMENT, SAID HEATDISSIPATOR RIBS BEING IN HEAT-CONDUCTIVE RELATIONSHIP WITH SAID WEBSEGMENT, EACH WEB SEGMENT BEING PROVIDED WITH A PAIR OF LONGITUDINALGROOVES EACH BEING SUBSTANTIALLY PARALLEL TO THE CONDUIT LONGITUDINALCENTRAL AXIS, SAID GROOVES HAVING LINEARLY GENERATED SIDEWALLS, SAIDSPACER MEANS COOPERATING WITH SAID GROOVES TO REMOVABLY SUPPORT ANDSPACE SAID WEB SEGMENTS ABOUT THE TUBE LONGITUDINAL CENTRAL AXIS THEOPPOSITE SIDE OF AT LEAST ONE WEB SEGMENT BEING INTEGRALLY PROVIDED WITHAT LEAST ONE SUPPORT MEMBER ADAPTED TO CARRY A HEAT GENERATINGELECTRONIC COMPONENT, SAID AT LEAST ONE SUPPORT MEMBER BEING INHEAT-CONDUCTIVE RELATIONSHIP TO SAID WEB SEGMENT, SAIDELECTRICALLY-INSULATIVE SPACER MEANS COMPRISING AN INTERMEDIATE PORTIONAND A PAIR OF TERMINAL SOCKET MEMBERS, EACH OF SAID TERMINAL SOCKETMEMBERS BEING SECURELY SURROUNDED WITH AN ELONGATE GROOVE OF ADJACENTLYDISPOSED WEB SEGMENTS, THE INTERMEDIATE PORTION OF THE SPACER MEANSBEING DISPOSED AT THE JUNCTURE OF THE RESPECTIVE ADJACENT WEB SEGMENTS.